Antibacterial activities of coumarin-3-carboxylic acid against Acidovorax citrulli

Fa-Di Zhu; Xin Fu; Huo-Chun Ye; Hai-Xin Ding; Liu-Shuang Gu; Jing Zhang; Yong-Xia Guo; Gang Feng

doi:10.3389/fmicb.2023.1207125

Antibacterial activities of coumarin-3-carboxylic acid against Acidovorax citrulli

Front Microbiol. 2023 Sep 20:14:1207125. doi: 10.3389/fmicb.2023.1207125. eCollection 2023.

Authors

Fa-Di Zhu^#¹, Xin Fu^#^{1

2}, Huo-Chun Ye^{1

3}, Hai-Xin Ding⁴, Liu-Shuang Gu¹, Jing Zhang^{1

3}, Yong-Xia Guo^{2

5}, Gang Feng^{1

3}

Affiliations

¹ Environment and Plant Protection Institute, Chinese Academy of Tropical Agricultural Science, Haikou, China.
² College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, China.
³ Key Laboratory of Monitoring and Control of Tropical Agricultural and Forest Invasive Alien Pests, Ministry of Agriculture, Haikou, China.
⁴ Key Laboratory of Organic Chemistry, Institute of Organic Chemistry, Jiangxi Science and Technology Normal University, Nanchang, China.
⁵ Key Laboratory of Low-Carbon Green Agriculture in Northeastern China of Ministry of Agriculture and Rural Affairs, Daqing, China.

^# Contributed equally.

Abstract

Coumarin-3-carboxylic acid (3-CCA), previously screened from natural coumarins, was found to possess strong antibacterial activity against Acidovorax citrulli (Ac). In order to further evaluate the activity of this compound against plant bacterial pathogens and explore its potential value as a bactericidal lead compound, the activity of 3-CCA against 14 plant pathogenic bacteria in vitro and in vivo was tested. Results showed that 3-CCA exhibited strong in vitro activities against Ac, Ralstonia solanacearum, Xanthomonas axonopodis pv. manihotis, X. oryzae pv. oryzae, and Dickeya zeae with EC₅₀ values ranging from 26.64 μg/mL to 40.73 μg/mL. Pot experiment results showed that 3-CCA had powerful protective and curative effects against Ac. In addition, the protective efficiency of 3-CCA was almost equivalent to that of thiodiazole copper at the same concentration. The results of SEM and TEM observation and conductivity tests showed that 3-CCA disrupted the integrity of the cell membrane and inhibited polar flagella growth. Furthermore, 3-CCA resulted in reductions in motility and extracellular exopolysaccharide (EPS) production of Ac while inhibiting the biofilm formation of Ac. These findings indicate that 3-CCA could be a promising natural lead compound against plant bacterial pathogens to explore novel antibacterial agents.

Keywords: Acidovorax citrulli; bactericidal activity; biofilm; coumarin-3-carboxylic acid; mechanism.

Grants and funding

This study was financially supported by the Hainan Province Science and Technology Special Fund (ZDYF2022XDNY213), the Key Laboratory of Low-carbon Green Agriculture in Northeastern China, Ministry of Agriculture and Rural Affairs, P. R. China (Grant No. LCGANE08), and the Fundamental Research Fund of the Academy of Tropical Agricultural Science (1630042022009).